package main

import (
    "context"
    "log"
    
    postal "github.com/sachin-duhan/postal-go"
    "github.com/sachin-duhan/postal-go/common/types"
)

func main() {
    // Initialize client with functional options
    client := postal.NewClient(
        postal.WithAPIKey("your-api-key"),
        postal.WithBaseURL("https://postal.example.com"),
        postal.WithDebug(true), // Enable debug logging
    )

    // Create a message
    message := &types.Message{
        To:       []string{"recipient@example.com"},
        From:     "sender@yourdomain.com",
        Subject:  "Hello from Postal-Go!",
        Body:     "This is a plain text email.",
        HTMLBody: `<h1>Hello!</h1><p>This is an <strong>HTML</strong> email.</p>`,
    }

    // Send the message
    result, err := client.SendMessage(context.Background(), message)
    if err != nil {
        log.Fatal(err)
    }
    
    if result.Success() {
        log.Printf("Message sent successfully! ID: %s", result.MessageID)
    }
}

client := postal.NewClient(
    postal.WithAPIKey("your-api-key"),
    postal.WithBaseURL("https://postal.example.com"),
    postal.WithTimeout(30 * time.Second),
    postal.WithMaxRetries(3),
    postal.WithRetryInterval(time.Second),
    postal.WithMaxConcurrency(10),
    postal.WithDebug(true),
    postal.WithMiddleware(customMiddleware),
)

message := &types.Message{
    To:       []string{"recipient@example.com"},
    From:     "sender@yourdomain.com",
    Subject:  "Invoice Attached",
    HTMLBody: "<p>Please find the invoice attached.</p>",
    Attachments: []types.Attachment{
        {
            Name:        "invoice.pdf",
            ContentType: "application/pdf",
            Data:        base64EncodedData,
        },
    },
}

// Create a logging middleware
loggingMiddleware := func(next http.RoundTripper) http.RoundTripper {
    return RoundTripperFunc(func(req *http.Request) (*http.Response, error) {
        log.Printf("Request: %s %s", req.Method, req.URL)
        resp, err := next.RoundTrip(req)
        if resp != nil {
            log.Printf("Response: %d", resp.StatusCode)
        }
        return resp, err
    })
}

client := postal.NewClient(
    postal.WithAPIKey("your-api-key"),
    postal.WithBaseURL("https://postal.example.com"),
    postal.WithMiddleware(loggingMiddleware),
)

result, err := client.SendMessage(ctx, message)
if err != nil {
    if postalErr, ok := err.(*types.PostalError); ok {
        if postalErr.IsRateLimit() {
            log.Println("Rate limited, retry later")
        } else if postalErr.IsUnauthorized() {
            log.Println("Invalid API key")
        } else if postalErr.IsServerError() {
            log.Println("Server error:", postalErr.Message)
        }
    }
    return err
}